Puberty timing influenced by 'imprinted' genes

The age at which girls reach sexual maturity is influenced by which parent their genes are inherited from, says a study.

The activity of these "imprinted" genes differs depending on from which parent the gene is inherited.

Some genes are only active when inherited from the mother, others are only active when inherited from the father.

"Both types of imprinted genes were identified as determining puberty timing in girls, indicating a possible biological conflict between the parents over their child's rate of development," researchers added.

"By studying genetic factors, we hope to better understand how puberty timing in girls is linked to important health conditions in women," said Joanne Murabito, an associate professor of medicine at Boston University's School of Medicine.

The findings come from an international study of more than 180,000 women involving scientists from 166 institutions worldwide.

The researchers identified 123 genetic variations that were associated with the timing of when girls experienced their first menstrual cycle.

Six of these variants were found to be clustered within "imprinted" regions of the genome.

Further evidence for the parental imbalance in inheritance patterns was obtained by analysing the association between these imprinted genes and timing of puberty in a study of over 35,000 women in Iceland.

"This is the first time that it has been shown that imprinted genes can control rate of development after birth," Murabito added.

The research appeared in the journal Nature.